1. Field of the Invention
The present invention relates generally to sunglasses. More particularly, the invention relates to attachments or mountings for releasably attaching prescription lenses onto sunglasses.
2. Description of the Prior Art
The use of sunglasses has become more prevalent over the years. Sunglasses are recognized as useful for the protection of the eyes against ultraviolet rays. In fashion, new designs and colors have made them increasingly attractive as part of a person's overall wardrobe. In outdoor sports and outdoor activities, they have gained increasing acceptance. In certain sports, bicycling for example, specially designed sport sunglasses have gone from the exception to standard equipment.
Approximately 30% of all persons who might use sunglasses have the need for prescription lenses, either eyeglass lenses or contact lenses. Contact lenses may be used with sport sunglasses. However, many sport sunglasses now available have lenses made of a relatively thin, high strength polycarbonate plastic having an often complex curvature. Prescription lenses cannot readily be made to conform to such shapes and are unavailable commercially.
With conventional sunglasses, those other than sport sunglasses, a prescription can be made and corrective lenses mounted on the frame. Other known combinations of prescription lenses and sunglass lenses include use of a clip-on sunglass lens over a prescription eyeglass lens. The reverse has also been done, prescription lenses have been clipped over the frame of a pair of sunglasses to provide the necessary correction.
Many of the sport sunglasses referenced above are made so that the lenses and nose-pieces can be easily separated from the frames. No one has previously supplied an interchangeable nose-piece or insert for readily mounting prescription lenses onto sport sunglasses.